Aortopulmonary electrical stimulator-pressure transducer

ABSTRACT

In an embodiment herein, an aortopulmonary stimulation method is provided including positioning at least one aortic electrode in or near the aorta, and using the at least one aortic electrode, to deliver stimulation to the aorta to decrease aortic after load.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. Non-Provisionalapplication Ser. No. 15/646,735 filed on Jul. 11, 2017, and claimspriority thereto under 35 U.S.C. 121. U.S. Non-Provisional applicationSer. No. 15/646,735 claims priority to Provisional Application No.62/344,923, filed on Jun. 2, 2016. All patent and literature referencescited in the present specification are hereby incorporated by referencein their entirety.

BACKGROUND

The degree of tension or stress on a heart muscle fiber as it contractsis termed the after load. Because pressure within the ventricles risesrapidly from a diastolic to a systolic value as blood is pumped out intothe aorta and pulmonary arteries, the part of the ventricle that firstcontracts due to an excitatory stimulation pulse does so against a lowerafter load than does a part of the ventricle contracting later.Therefore, after load is the end load against which the heart contractsto eject blood. Many factors may influence the after load, one of whichis the aortic pressure the left ventricular muscle must overcome toeject blood. A higher aortic/pulmonary pressure increases the after loadon the left/right ventricle, respectively. The tension on the musclefibers in the heart wall is the pressure within the ventricle multipliedby the volume within the ventricle divided by the wall thicknessaccording to Laplace's law. This ratio is another factor used indetermining the after load. By applying pressure on certain portions ofthe heart, after load can be greatly reduced or eliminated.

Prior art devices which attempt to address the aforementioned problemsinclude pump-devices which surround certain portions of the heart tostimulate the portions. Other prior art devices include components thatcross the pulmonic and tricuspid valves in order to stimulate thepulmonary artery.

Some other methods of attempting to modulate after load may include anextra-aortic balloon pump enabled to encircle the ascending aorta. Thisrequires dissecting the aorta free from the pulmonary artery, which itabuts.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description briefly stated above will be rendered byreference to specific embodiments thereof that are illustrated in theappended drawings. Understanding that these drawings depict only typicalembodiments and are not therefore to be considered to be limiting of itsscope, the embodiments will be described and explained with additionalspecificity and detail through the use of the accompanying drawings inwhich:

FIG. 1 provides a view of an embodiment of the placement of the deviceon a heart, in one example;

FIG. 2 provides a schematic of an aortopulmonary electrical stimulationembodiment;

FIG. 3 provides a non-limiting embodiment of an aortopulmonaryelectrical stimulation device including a sleeve array.

DETAILED DESCRIPTION OF THE DRAWINGS

For the purposes of promoting an understanding of the principles andoperation of the invention, reference will now be made to theembodiments illustrated in the drawings and specific language will beused to describe the same. It will nevertheless be understood that nolimitation of the scope of the invention is thereby intended, suchalterations and further modifications in the illustrated device, andsuch further applications of the principles of the invention asillustrated therein being contemplated as would normally occur to thoseskilled in the art to which the invention pertains.

It is to be noted that the terms “first,” “second,” and the like as usedherein do not denote any order, quantity, or importance, but rather areused to distinguish one element from another. The terms “a” and “an” donot denote a limitation of quantity, but rather denote the presence ofat least one of the referenced item. The modifier “about” used inconnection with a quantity is inclusive of the stated value and has themeaning dictated by the context (e.g., includes the degree of errorassociated with measurement of the particular quantity). It is to benoted that all ranges disclosed within this specification are inclusiveand are independently combinable.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise theseterms do not denote a limitation of quantity, but rather denote thepresence of at least one of the referenced item. Furthermore, to theextent that the terms “including,” “includes,” “having,” “has,” “with,”or variants thereof are used in either the detailed description and/orthe claims, such terms are intended to be inclusive in a manner similarto the term “comprising.” Moreover, unless specifically stated, any useof the terms first, second, etc., does not denote any order, quantity orimportance, but rather the terms first, second, etc., are used todistinguish one element from another.

The inventor has identified a condition of ambulatory heart failuretreatment is after load reduction. Issues with after load often appearin cardiac surgery procedures. In order to remedy and/or prevent issuesassociated with these procedures, such as after load, the inventor hasidentified a novel method that induces beneficial neuro endocrinechanges in a subject by pressure-induced activation of aorticbaroreceptors.

The inventor has discovered that by stimulating the aorta and pulmonaryartery with electrodes or otherwise as described herein, the pulmonaryand aortic after load may be decreased in a measurable and adjustablemanner. This way the effects of the stimulation will be measurable, andany adverse effects may be avoided. Methods currently used in the art toattempt to decrease afterload include IV medications, which result insubstantial side effects. For example, side effects include an increasein myocardial oxygen demand. Other medications including nitroglycerinand nitride also result in damaging side effects when used. Theinventive methods described herein would eliminate the need for the verycostly intravenous drips currently used perioperatively during heartsurgery procedures.

To eliminate the risks of dissecting between the aorta and the pulmonaryartery, the inventor has discovered that both the aorta and thepulmonary artery may be encircled through the transverse pericardialsinus, taking advantage of a natural space and eliminating any risksassociated with dissecting between the aorta and pulmonary artery.

Various embodiments described herein relate to a method. Otherembodiments relate to a device. According to the various electrodeembodiments described, at least one electrode used and is positioned inor on the aorta. Stimulation is applied using the at least oneelectrode. In other electrode embodiments, at least one electrode ispositioned in or on the aorta and another electrode is positioned in oron a pulmonary artery. Stimulation is applied using at least one of theelectrodes. Stimulation may be applied using both electrodes, and may beapplied either simultaneously or one at a time. The stimulation may bevaried in strength, duration, and sequence. The stimulation may becontrolled by way of a control unit as described herein.

Many of the benefits of this device are achieved by activatingbaroreceptors. A baroreceptor includes any sensor of pressure changes,such as sensory nerve endings in the wall of the auricles of the heart,cardiac fat pads, vena cava, aortic arch and carotid sinus, that issensitive to stretching of the wall resulting from increased pressurefrom within, and that functions as the receptor of the central reflexmechanism that tends to reduce that pressure. Additionally, abaroreceptor includes afferent nerve trunks, such as the vagus, aorticand carotid nerves, leading from the sensory nerve endings. Stimulatingbaroreceptors inhibits sympathetic nerve activity (stimulates theparasympathetic nervous system) and reduces systemic arterial pressureby decreasing peripheral vascular resistance and cardiac contractility.Some embodiments described herein stimulate baroreceptor sites in thepulmonary artery and/or in the aorta. Consequently, in anotherembodiment, using electrical stimulation to activate the baroreceptorsmay be accomplished with or without a pump. In order to monitor theeffectiveness of the baroreceptor response, transducing the pressure inthe vessels would be advantageous. Consequently, in an embodiment, theinventor has discovered an aortopulmonary electrical stimulator and/orpressure transducer array to achieve the abovementioned functions. Thedevice may be minimally invasive, in an embodiment. The device may beused with minimal incisions.

One embodiment may include a transient array including leads configuredto pass through a chest wall and associate with a control unit externalto the subject. The control unit may be used to activate and/orinactivate the device, as well as to control the functions and featuresof the device as will be described in greater detail herein. The controlunit may include stimulator circuitry, which may include modules toinitiate or generate electrical pulses for delivery to the electrodes.The stimulator circuitry may be a component of the microprocessor. Themicroprocessor may be used to vary the amplitude of the stimulationpulse, the frequency of the pulse, the burst frequency, or the dutycycle of the pulse and the wave morphology of the pulse.

In one particular, non-limiting embodiment, the array and/or the leadsmay be disposable. In an embodiment, the leads may be removable from thesubject perioperatively. The leads described herein may bepercutaneously placed, in another non-limiting embodiment. In anembodiment, proximal and distal arrays surrounding the aorta andpulmonary arteries in the transverse pericardial sinus may be used.Tape-like component may be used to insulate the components of the devicefrom surrounding structures, in a non-limiting embodiment.

Another embodiment may include a device including an implanted controlunit which may be implanted into the body of the subject connecting tothe leads of the device. In one non-limiting embodiment, the controlunit may be implantable in a sub-pectoral location in the subject.

Non-limiting embodiments herein include an array which may include anarray of output electrodes organized such that the aorta and thepulmonary artery may be individually stimulated. The arrays may be gatedto provide various levels of stimulation to the aortic and pulmonaryarteries as needed.

In an embodiment, strain gauges or other measurement devices know tothose skilled in the art may be used to measure aortic and pulmonaryartery pressures.

In another embodiment, additional cardiac leads may be added forbiventricular pacing or defibrillator. The control unit may includewired or wireless connectivity for the communication of information anddata to and from the control unit. in a non-limiting example, Bluetoothwireless technology may be employed.

The terms “subject” or “patient” may be used interchangeably herein. Theterms include any animal or human subject.

Various embodiments of the present subject matter relate to a lead.Various lead embodiments comprise a lead body including a first portion,and at least a first branch. Other embodiments include a lead bodyincluding a first portion and at least a first branch and a secondbranch. The first portion has an end adapted to connect to animplantable medical device. The first branch may be connectable toeither one of an aorta or a right or left pulmonary artery. The secondbranch may be connected to the first portion at a bifurcated region, inone non-limiting embodiment. The first branch may include a distal endadapted to be placed on or around the aorta, or fed into the aorta tosecurely position at least one electrode on or within the aorta. Thesecond branch includes a distal end adapted to be placed onto or aroundor fed into a pulmonary artery to securely position at least oneelectrode on or within the pulmonary artery.

Various lead embodiments implement a number of designs, including anexpandable stent-like electrode with a mesh surface dimensioned to abuta wall of a predetermined blood vessel, a coiled electrode(s), a fixedscrew-type electrode(s), and the like. Various embodiments place theelectrode(s) inside the blood vessel, into the wall of the blood vessel,or a combination of at least one electrode inside the blood vessel andat least one electrode into the wall of the blood vessel. The neuralstimulation electrode(s) can be integrated into the same lead used or inanother lead.

In one embodiment, a method for placing an electrode sleeve arraycomprising a sleeve body having a first end and a second end, and two ormore electrodes, into a patient is provided. The method includesinserting a first end of a sleeve body around an aorta and pulmonarytrunk through a transverse pericardial sinus, and affixing the first endof the sleeve body to a second end of the sleeve body with a fastener,such that the sleeve body encircles the aorta and the pulmonary artery.

In another embodiment, a method including positioning an aorticelectrode in or near the aorta; and using the aortic electrode, todeliver stimulation to the aorta to decrease aortic after load isprovided. In another non-limiting embodiment, the method may includepositioning a pulmonary artery electrode in or near the pulmonary arteryand using the pulmonary artery electrode to deliver stimulation to thepulmonary artery to decrease pulmonary artery after load.

In yet another embodiment, an aortopulmonary stimulation device isprovided. The device includes an electrode sleeve array comprising asleeve body, and two or more electrodes, the sleeve body comprising afirst end and a second end for placement around the aorta and thepulmonary artery, in one embodiment, wherein upon placement of thesleeve array, at least a first electrode contacts the aorta, and atleast a second electrode contacts the pulmonary artery. The deviceincludes one or more leads connecting the electrode sleeve array to acontrol unit, the control unit for providing electrical stimulation tothe electrode sleeve array, wherein upon initiation of electricalstimulation to the electrode sleeve array, the two or more electrodesdeliver differential stimulation to the aorta and/or the pulmonaryartery. In an alternative embodiment the sleeve body may be placedaround the aorta or the pulmonary artery. In yet another embodiment, afirst sleeve array may be placed around the aorta, and a second sleevearray may be placed around the pulmonary artery.

Turning to the drawings, FIG. 1 provides a side view of a heart 201including a superior vena cava 202, aorta 203 and pulmonary artery 204.A first electrode 206 may be placed in or on the aorta 203, and a firstlead 207 connecting the first electrode to a control unit 210. A secondelectrode 208 may be placed in or on the pulmonary artery 204 and asecond lead 209 connecting the second electrode 208 to the control unit210. The control unit 210 may include a microprocessor 212 and a powersource 214. The control unit 210 may be used to initiate the electrodes206, 208 to stimulate the aorta 203 and the pulmonary artery 204. Boththe aorta 203 and the pulmonary artery 204 may be simultaneouslystimulated or may be stimulated at different times. The electrodes 206,208 may be stimulated independently of one another to differentiallystimulate the aorta and pulmonary artery.

FIG. 2 provides a schematic view of the device 100, wherein a controlunit 110 including a microprocessor 112, and a power source 114 isprovided. A first electrode for aortic placement 116 is associated withthe control unit 110, and a second electrode, for stimulation of thepulmonary artery 118 is associated with the control unit 110.

FIG. 3 provides a side view of a device embodiment 300, wherein a sleevearray 310 is placed on the aorta 312 and the pulmonary artery 314. Whenthe sleeve array 310 is placed on the aorta 312 and the pulmonary artery314, at least a first electrode 316 contacts the aorta 312, and at leasta second electrode 318 contacts the pulmonary artery 314. Electricalsimulation is delivered to the aorta 312 and the pulmonary artery 314 byway of electrical leads 320, which are connected to an electrical pulsegenerator, i.e., a control unit 322. A fastening device 324 may be usedto affix the sleeve array 310 to the aorta 312 and pulmonary artery 314.

In one embodiment, a method including positioning at least one aorticelectrode in or near the aorta, and using the at least one aorticelectrode, to deliver stimulation to the aorta to decrease aortic afterload is provided. In a further embodiment, the method includespositioning at least one pulmonary artery electrode in or near thepulmonary artery and using the at least one pulmonary artery electrodeto deliver stimulation to the pulmonary artery to decrease pulmonaryartery after load. In one example baroreceptors are stimulated. Inanother embodiment, the method includes delivering a variable level ofstimulation to the aorta. In yet another embodiment, the method includesdelivering a variable level of stimulation to the pulmonary artery. Infurther embodiment, the method may include a device comprising one ormore strain gauges configured to measure the aortic and/or pulmonaryartery pressure. In some examples, based on the pressure detected, avariable stimulation of the aorta and/or pulmonary artery is executed.

In another embodiment, a first electrode sleeve array comprising asleeve body and at least one aortic electrode may be provided, wherein amethod of reducing after load includes inserting a first end of thesleeve body around the aorta and pulmonary trunk through a transversepericardial sinus, and affixing the first end of the sleeve body to asecond end of the sleeve body, such that the sleeve body encircles theaorta and the pulmonary artery.

The method may further include wherein the sleeve body of the devicefurther comprises a fastener, and the method includes affixing the firstend of the sleeve body is to the second end of the sleeve body via thefastener

In yet another non-limiting embodiment, a method for placing anelectrode sleeve array comprising a sleeve body having a first end and asecond end, and two or more electrodes, into a patient, includesinserting a first end of a sleeve body around an aorta and pulmonarytrunk through a transverse pericardial sinus, and affixing the first endof the sleeve body to a second end of the sleeve body with a fastener,such that the sleeve body encircles the aorta and/or the pulmonaryartery.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope are approximations, the numerical values set forth inspecific non-limiting examples are reported as precisely as possible.Any numerical value, however, inherently contains certain errorsnecessarily resulting from the standard deviation found in theirrespective testing measurements. Moreover, all ranges disclosed hereinare to be understood to encompass any and all sub-ranges subsumedtherein. As a non-limiting example, a range of “less than 10” caninclude any and all sub-ranges between (and including) the minimum valueof zero and the maximum value of 10, that is, any and all sub-rangeshaving a minimum value of equal to or greater than zero and a maximumvalue of equal to or less than 10, e.g., 1 to 7.

While one or more embodiments of the present invention have been shownand described herein, such embodiments are provided by way of exampleonly. Variations, changes and substitutions may be made withoutdeparting from the invention herein. Accordingly, it is intended thatthe invention be limited only by the spirit and scope of the appendedclaims. The teachings of all references cited herein are incorporated intheir entirety to the extent not inconsistent with the teachings herein.

What is claimed is:
 1. A method, comprising: positioning at least oneaortic electrode in or near the aorta; and using the at least one aorticelectrode, to deliver stimulation to the aorta to decrease aortic afterload.
 2. The method of claim 1, further comprising: positioning at leastone pulmonary artery electrode in or near the pulmonary artery and usingthe at least one pulmonary artery electrode to deliver stimulation tothe pulmonary artery to decrease pulmonary artery after load.
 3. Themethod of claim 1, wherein baroreceptors are stimulated.
 4. The methodof claim 1, comprising delivering a variable level of stimulation to theaorta.
 5. The method of claim 2, comprising delivering a variable levelof stimulation to the pulmonary artery.
 6. The method of claim 1,further comprising one or more strain gauges configured to measure theaortic and/or pulmonary artery pressure.
 7. The method of claim 6,wherein based on the pressure detected, a variable stimulation of theaorta and/or pulmonary artery is executed.
 8. The method of claim 1,further comprising a first electrode sleeve array comprising a sleevebody and at least one aortic electrode, the method comprising insertinga first end of the sleeve body around the aorta and pulmonary trunkthrough a transverse pericardial sinus; and affixing the first end ofthe sleeve body to a second end of the sleeve body, such that the sleevebody encircles the aorta and the pulmonary artery.
 9. The method ofclaim 8, wherein the sleeve body further comprises a fastener, such thatthe first end of the sleeve body is affixed to the second end of thesleeve body via the fastener.
 10. A method for placing an electrodesleeve array comprising a sleeve body having a first end and a secondend, and two or more electrodes, into a patient, comprising: inserting afirst end of a sleeve body around an aorta and pulmonary trunk through atransverse pericardial sinus; and affixing the first end of the sleevebody to a second end of the sleeve body with a fastener, such that thesleeve body encircles the aorta and/or the pulmonary artery.